oil viscosity

Thu Jun 30, 2005 11:38 am

Running my BN last night in about 90 F mowed for about a half an hour.the oil pressure continued to drop ran fine. After I got back to the garage I checked the oil and it ran out like coolant At first I thiught is was coolant but after closer inspection was oil. I have 10 w 30 in it now
The pressure holds but as it warms it starts to drop Absolutly no smoke from the stack. Should I use a different oil?
Thanks PWL

Thu Jun 30, 2005 12:42 pm

I'm no expert, but why not try straight 30w in the summer and switch back to 10-30w in the winter.......... :idea: :?:

Thu Jun 30, 2005 3:46 pm

Ron L wrote:I'm no expert, but why not try straight 30w in the summer and switch back to 10-30w in the winter.......... :idea: :?:


10w30 is 10 weight oil with 30 weight lubricating abilities.

I would try what Ron L suggests & go straight 30w.

Fri Jul 01, 2005 5:24 am

Thanks Guys
I changed to straight 30 last night went and mowed for about 15 min it did move down a little, but held good ,was'nt as hot last night upper 80's but seemed to be OK thanks
Was Thinking this in the first place, but it's nice when someone confirms what you have been considering.
Thanks again
PWL

Fri Jul 01, 2005 7:35 am

Ron L wrote:I'm no expert, but why not try straight 30w in the summer and switch back to 10-30w in the winter.......... :idea: :?:

That's what I have done on my cub for years. makes cold weather starting a little easier.

Thu Jul 14, 2005 6:48 pm

When the local (microscopic) pressure reaches 17 gigapascals a molecule of zinc phosphate, a common oil additive since 1930's, forms addtional bonds with other molecules of zinc phosphate and becomes a 3 D structure that prevents the deformation of steel and cast iron with a thin (very thin) dense and rubbery film and protects the metal.

Aluminum begins to deform at 7 gigapascals. Oil scients are looking for an additive that will protect at pressure less than 7 gigapascals but still have not found one.

Boy!! am I glad the cub engine is not aluminum.


article found in Science March 11 issue.